Universal air handling troffer frame



April 14, 1970 G. E. MULV EY ETAL UNIVERSAL AiR HANDLiNG TROFFER FRAME 2Sheets-Sheet 1 Filed Dec. 4, 1967 FIG 4 FIG 5 6 INVENTORS FIG GERARD E.MULVEY GEORGE April 14, 1970 G. E. Mum/Ev T AL 3, 2

UNIVERSAL AIR HANDLING TROFFEB FRAME 2 Sheets-Sheet 2 1 Filed Dec. 4.1967 INVENTORS EE 1 G United States Patent Office 3,506,822 PatentedApr. 14, 1970 US. Cl. 240-9 6 Claims ABSTRACT OF THE DISCLOSURE Asupporting frame for use with light trofiers of the kind employingfluorescent lamps. In order to support the support the light troffers inposition in the ceiling, the frames are constructed separately and areof a readily variable design to accommodate changes in length, withoutaffecting the light trofi'ers. Also provided is a method for customdesigning of lighting installations at very low cost without alteringthe light troffers, and as such is adaptable for use with or without airhandling facilities without revealing any apparent alteration to thenaked eye. The troffer frames are preferably formed of extruded materialsuch as aluminum and provided with concealed attachment flanges to whichthe sheet metal trofler boxes can be attached.

This invention relates to a frame for light troffers having air handlingfacilities.

Current building systems employing false ceilings usually incorporatefluorescent lighting systems which are recessed flush with the falseceiling. In order to reduce the number of openings in the ceiling, it isa common practice to incorporate air handling slots alongside some orall of the light troffers to accommodate the air conditioning needs ofthe space, some of such slots being the air delivery slots and othersbeing the return air slots. In order to facilitate installation of suchlight trofiers, and their connection to the air delivery and returnducts, the light trotfers and air handling delivery and return openingmeans are usually formed in a single integral structure fitting withinan opening of predetermined size in the false ceiling. Various forms ofsuch air handling light troffer assemblies have been manufactured in thepast, but have suffered from a variety of defects. Thus, for example, itis commonplace that air handling openings in ceilings and the like forair conditioning lead to an accumulation of dirt around the edges of theopening, and also to a discolouration of the paint, or other surfacematerial. One way in which this can be overcome is to employ bigger andbigger openings leading to reduced air flow velocities but such largeropenings tend to be unsightly. In addition, the use of over sized slotsaround the lens of the lighting fixture itself is unacceptable for otherreasons. In general, the design of a false ceiling is such that the sizeof the opening in the ceiling is determined by the design of the ceilingand cannot be enlarged to accommodate greater slots. Thus if it isattempted to increase the size of the slots, it can generally speakingonly be achieved at the expense of a reduction in the size of the lensof the lighting fixture. This leads to an increase in brightness of thelens which is itself the subject of restrictions under accepted buildingpractices. Thus, it will be apparent that designs of air handlingopenings in the past have generally been directed to obtaining thesmallest possible opening with a resultant high rate of accumulation ofdirt and discolouration.

A further disadvantage of prior light troffer designs is that the use ofslotted air handling openings in some of the light troffers in an arealead to a non-uniform appearance with some of the troffers incorporatingslotted openings and others being blank. In addition, the slotsthemselves are unsightly since they constitute black openings in theceiling without contributing to the aesthetic appearance of thetrotfers.

A still further disadvantage of prior art troffers, lay in the fact thatin general, they were manufactured wholly or substantially completely ofsheet metal and did not readily lend themselves to minor adjustments inlength. In addition, they could not ingeneral span a distance greaterthan about four feet, the length of the normal mercury tube, whichrestricted their use in various ways. Thus, when using four foottroffers in a ceiling designed with four foot modules or modules of fourfeet by eight feet, the troffers could span the distance between two ofthe ceiling supporting Ts without difficulty, and when placed end to endso as to achieve the most efficient light distribution pattern theywould be spaced apart only by the width of such T. However, it wasgenerally speaking not possible to use such standard four foot troiferswith ceiling which did not incorporate a four foot module. Thus forexample, when using a ceiling designed on a five foot module, it wasformerly necessary to provide some other means of supporting thetroffers, other than simply resting them on the ceiling T. In additionto providing some other form of supporting means, it was also necessaryto fill the spaces at one or other end of the trolfers thereby breakingup the pattern of the ceiling.

In addition, the dimensions of a ceiling are generally speaking subjectto fairly broad tolerances due to variations in the exact dimensions ofthe outside walls of the building, particularly in the case of pouredconcrete construction. As a result, it frequently occurred that thetroifer at one or other end of a row of troffers required shortening toaccommodate such tolerances and the sheet metal construction of priorart trolfers caused great difficulty.

When arranging partitions for a space illuminated by rows of lighttrotfers, it is necessary to arrange that the partitions do not overlapthe lenses of the troffers. Thus some spacing between troffers arrangedend to end becomes necessary, making the use of a five foot ceilingmodule, coupled with light troffers somewhat shorter than five feet, andaccommodating four foot mercury tubes, as a highly desirable solution.However, due to the problems mentioned above in connection withsupporting the standard four foot troflers in a five foot ceiling, asatisfactory solution to this problem has never been achieved at aneconomical price.

The invention therefore seeks to provide as a principal objective, auniversal frame work upon which the light troffer can be mounted whichis cheap and simple to construct, which may incorporate air handlingslots if desired with only minor structural alterations and without inany way alterating the appearance, and in which such slots are to allintents and purposes invisible, which frame may readily be arranged tospan varying spaces between ceiling TS and which may readily be adjustedor modified as to length without the necessity for alterating the lighttroffer itself.

More particularly, it is an objective of the present invention toprovide a light trolfer frame of inverted channel shaped constructionadapted to incorporate air handling slots in one side wall of suchchannel, the channel being inaccessible to light from the troffersthereby concealing the air handling slots from view.

More particularly, it is an objective of the present invention toprovide a frame for light troflers which is formed from continuouslengths of channel shaped stock, cut into lengths to span the spacingdesired and having upwardly directed attachment means for attachment ofa light troffer thereto.

More particularly, it is an objective of the present invention toprovide a frame for light troffers which itself incorporates supportingmeans for engagement with the adjacent ceiling Ts.

More particularly, it is an objective of the present invention toprovide a frame for light trolfers incorporating end panels at each endof the troffer whereby the troffers themselves can be made somewhatshorter than the spacing between the Ts, the end panels on the troiferframe filling the space threbetween thereby rendering it possible toerect partitions passing between any two such light trolfers arrangedend to end without the necessity of modifying the light troffers orreplacing them with shorter troifers.

The foregoing and other objectives of the invention will become apparentfrom the following description of a preferred embodiment of theinvention which is given here by way of example only with reference tothe various views and diagrams in which like reference devices refer tolike parts thereof throughout the various views and diagrams and inwhich;

FIGURE 1 is a perspective illustration of a troffer frame according tothe invention showing the light troffer and mercury tubes in phantomform supported in location in a ceiling partially cut away to reveal theconstruction thereof;

FIGURE 2 is a section along the line 2-2 of FIG- URE 1 showing one sideof the frame and light troifer coupled to an air handling duct;

FIGURE 3 is a greatly enlarged perspective illustration of the cornerdetail of a frame according to the invention;

FIGURE 4 is an enlarged secion of the trolfer frame according to theinvention along the line 4-4 of FIG- URE 1 according to one embodimentthereof;

FIGURE 5 is a section corresponding to the section 44, showing anotherembodiment of the troffer frame suitable for use with alternative formsof ceiling construction; and

FIGURE 6 is a section along the line 66 of FIGURE 1 showing the detailsof the end construction of the troffer frame.

From FIGURES 1 and 2 it will be noted that these illustrations show aconventional form of ceiling construction comprising a criss crossnetwork of supporting Ts 10 supported at intervals by wires 11, andproviding support for ceiling tiles 12. In this embodiment, the basicceiling module is five feet square, each module being filled by twotiles 12, five feet long by eighteen inches wide, and between them atrolfer frame, indicated as 20, five feet long by two feet wide,although, obviously other forms of ceiling modules may be accommodatedaccording to the practice of the present invention without departingfrom the scope of the invention.

The trolfer frame according to the invention comprises side membersindicated as 20, end members 21 and, where desirable, there may beprovided one or more intermediate members 22 running one way or theother between either end members 21 or side members 20, depending uponthe desired dimensions of the frame, and the light characteristics ofthe particular troffer employed. A trofier indicated in this example inphantom and shown by the reference T is attached to the frame side andend members 20 and 21, and is provided with conventional fluorescentlamps and lenses L. In FIGURE 2 an air duct D is shown merely by way ofexample, being attached to frame side member 20 to be understood thatthe duct D may be either the air delivery or the air return duct, therebeing no material difference for the purposes of the invention apartfrom the fact that the air delivery ducts would normally be connectedwith light fixtures around the outside wall of the building? and the airreturn ducts would normally be connected with light fixtures groupedaround the central portion of the space. The side member 20 of thetrolfer frame will be seen to comprise an inverted channel shapedsection having inner and outer channel side walls 23 and 24 and achannel upper wall 25, together defining three sides of a rectangle, inthis preferred embodiment the lowermost portion of which is open todefine a continuous open mouth indicated at 26. In order to detach frameside member 20 to a light trotfer such as T, an attachment flange 27 isprovided along the upper sides of channel upper wall 25 therebypermitting self-tapping screws such as 28 to be fastened therethrough atintervals, without interfering with the appearance of channel upper wall25.

In the embodiment of FIGURES 1, 2, 3 and 4, channel side member 20designed so as to be self supporting on ceiling Ts 10. For this purpose,a horizontal rib member 29 is formed along the outer surface of outerchannel wall 24 being preferably spaced above the lowermost limitthereof by a distance equal to the thickness of ceiling T 10, whereby toachieve a uniform flat appearance as shown.

Frame end members 21 are similarly provided with inner and outer channelwalls 30 and 31 and channel upper wall member 32 defining a rectangularconfiguration identical with that of channel side member 20 and havingan open mouth 33, whereby to provide an identical uniform appearancearound all four sides of the lighting fixture. A flange member 34 isarranged along the upper surface of channel upper wall 32 but of reducedheight as compared with flange 27, since there is generally speaking noneed to attach the light trofler T at these points, the main purpose offlange 34 being merely to control the location of lens L, althoughobviously if additional attachment is felt to be necessary, dependingupon the design of the particular light troffer, flange 34 could beincreased in height to permit its use for attachment as in the case offlange 27. In this preferred embodiment, it will be understood that thelength of frame side members 20 is preferably somewhat less than thelength between ceiling Ts 10, whereby to provide spacing between theends of adjacent light ing fixtures to permit the erection of oflicepartitions at any desired location in the space. In order to fill thespace between frame end members 21 and the adjacent ceiling T5 10,extension members 35 are formed integrally with the lowermost edge ofouter channel walls 31 of frame end member 21, having an under surfacewhich is designed to lie in the same plane as the under surface ofceiling Ts 10 and thereby present a uniform flat appearance. Horizontalsupporting ribs 36 are formed on the outer edges of extension members35, and being in a plane offset with relation to the plane of extensionmembers 35 whereby to lie on the horizontal portion of ceiling Ts 10 andprovide additional support. Naturally, the width of extension members 35will depend to some extent upon the particular design of the ceilingmodule, and also upon the anticipated maximum width of partitions whichwill be erected in the space at some future time. For example, butwithout limitation, in the presently preferred embodiment, the ceilingTs 10 may be one and a half inches wide, and the extension members 35may be approximately two inches or a little more in width, therebygiving a total of between five and a half and six inches available forerection of partitions between the ends of adjacent lighting fixtures,without in any way impairing either the efficiency or the aestheticappearance of the fixtures. It will be understood that the trofferframes according to the invention may be employed both with and withoutair handling facilities, without in any way altering the appearance ofthe lighting fixture to the naked eye. Thus when it is desired toconnect air handling facilities, all that is required is to for-m aseries of air handling slots 37 in the outer channel walls 24 of frameside members 20, and air handling duct of standard design such as theduct being shown in FIG- URE 2, may be connected for either delivery orreturn air.

The construction of the corners of the trolfer frame according to theinvention are shown in FIGURE 3. It will be noted that frame side member20 and frame end member 21 are each cut through their respective innerand outer side walls 23 and 24 and inner side walls 30 and 31 and upperwalls 25 and 32 at angles of 45, and welded together as at 38 aroundonly their outer and upper surfaces whereby such weld 38 is completelyconcealed from the naked eye. While the particular construction of atrolfer frame according to the invention may be subject to variation indesign either with a view to altering the appearance, or due to the needto provide greater support for lenses L or due to variations in theceiling module, in the presently preferred embodiment it is founddesirable to provide an intermediate frame member 22 running parallel toside members 20 and attached at each end to end members 21 by similarwelding techniques. Intermediate member 20 is of identical constructionto side members 20 but without the provision of supporting rib 29 andobviously, no air handling slots 37 are provided. Obviously, althoughnot illustrated, it would be possible to add a further intermediatemember 22 running the opposite way at right angle to intermediate member22 as shown, if a lighting fixture of greater size requiring furthersupport for lenses L were required.

According to a further embodiment of the invention, as shown in FIGURE5, where other means of support for the lighting fixture are provided inthe building design, and where some other form of ceiling support otherthan celing T are employed, for example, side member 20 may be designedas shown in FIGURE 5, being substantially identical to the side members20 shown in FIGURE 4, but without the use of supporting rib 29.Alternatively, a junction flange such as is shown in phantom form inFIGURE 5 and illustrated as reference 39 may be provided at an angle, iffor example, it is desired to employ a plastered ceiling construction.

It is to be understood that by the use of troffer frames according tothe invention, a rigid integral frame work is provided of material whichis particularly suited for economical production in any length required,preferably employing aluminum as the material, and forming I it into thedesired shape by means of extrusion, although other materials andmethods of construction are obviously suitable. The use of a deeprectangular channel section provides a rigid girder like memberproviding great resistance to deflection under the weight of theassociated light trotfer, while also permitting the incorporation of airhandling slots in a highly advantageous manner. Thus, the deep channelsection may preferably be painted or coated with a dark matt surface,and when placed alongside the principal source of direct lighting namelythe lens L, will in fact appear to be totally black to the naked eye andit will not be possible to see how deep such a channel may be nor whatmay be concealed within it. The air handling slots formed within theouter channel wall in such a channel will generally speaking be thepoint around which the discolouration and dirt will accumulate, sincethey are the points of greatest restriction, the channels themselvesdefining considerably greater volume available for air flow. Such dirtand discolouration will generally speaking be completely concealed orhidden thus avoiding staining of the ceiling and requirement forfrequent and costly maintenance. In the case of buildings havingceilings of varying dimensions, minor adjustments may be made to thelength of the trotfer adjacent to one end of a row of trotfers by simplycutting off a certain amount of an extension member on one of the frameend members. Alternatively, if greater adjustment is required, it ispossible at very little extra cost to reduce the overall length of theframe side members without in any way affecting the construction of thelight trotfers themselves, the ends of which may simply be permitted tooverhang the frame end members.

It is to be understood that according to the invention, the trofferframe may be employed with various different kinds of ceilingconstruction other than that illustrated. For example, the ceiling tilesmay be supported by other means such as H section members fitting withinthe grooves in the tiles in known manner thereby providing concealedsupport. Alternatively, the ceiling may be of plaster construction, inwhich case the light troffer and troffer frames attached thereto will besupported by some other means such as wires or steel rods connected tothe floor above whereby to suspend the light troffers at the desiredlevel in the ceiling. Other means such as yoke or braces extending overthe light troffers and engaging the ceiling supporting system in wellknown manner are also within the scope of the invention.

It will also be appreciated that while the invention has been describedin connection with light troffers employing recessed lenses, that thelocation of the lens in relation to the construction of the trotferframe is a matter of choice, and obviously, the lens may be suspendedflush with or even below the trotfer frame without departing from thescope of the invention. Furthermore, when it is desired to construct aframe in which the frame end members do not incorporate extensionmembers, at one or other ends, then the frame end member section maymerely be replaced by a section of the frame side members, withoutdefecting any substantial alteration in the appearance of the trotferframe to the naked eye. This may be particularly advantageous when it isdesired to arrange troffer frames of reduced lengths close to a Wall.

What we claim is:

1. An integral air handling supporting frame for attachment to a lighttrotfer having an open lower side to form therewith a lighting fixtureadapted to be supported in a ceiling, said frame supporting the lens ofsaid lighting fixture independently thereof and providing the visibleportion of said lighting fixture, and comprising;

a pair of frame side members of equal length;

a pair of frame end members of equal length;

means joining said side members and end members at corners at rightangles to one another forming the same into an integral rectangularframe, said side members and said end members defining in section anidentical recessed upwardly extending channel having parallel inner andouter side walls and a top wall normal to said side walls, said channelbeing continuous around said side and end members when the same areassociated together to form a said frame and forming a light trap withrespect to light radiating from a light troffer atached to said frame;

lens supporting means defined by said side and end members lying in acommon plane for supporting a lens of a said lighting fixtureindependently of said fixture;

concealed attachment means formed on the upper side of said side membersat least for attachment around said open side of said light troffer; and

air handling slot means formed in said frame side members.

2. A support frame as claimed in claim 1 including an attachment flangeextending continuously along the upwardly directed portions of said sidemembers, and attachment holes formed therethrough at intervals forfastening to said light trofr'er.

3. A support frame as claimed in claim 1 including support rib meansformed along said outer side walls of said frame side members at leastfor interengagement by and with portions of the ceiling surrounding saidlighting fixture.

4. A support frame as claimed in claim 1 including extension meansformed integrally with said frame end members extending outwardlyendwise therefrom.

5. A support frame as claimed in claim 1 wherein said top Walls of saidside and end members lie in a common plane and constitute said lenssupporting means and support and locate said lens independently of saidlight troffer in a plane spaced above the lower edges of said side Wallsof said side and end members, recessing said lens within said framemembers and maximizing the open area thereof for passage of lighttherethrough.

6. A support frame as claimed in claim 1 wherein said lighting fixtureincorporates two lenses and including a further intermediate framemember extending between said frame end members midway therealong anddefining in section the same upwardly extending channel as said frameside and end members, whereby to provide intermediate lens support meanspermitting said lenses to be supported side by side. 7

References Cited UNITED STATES PATENTS 2,846,569 8/ 1958 Frizzell et a1.3,103,868 9/1963 Kodaras. 3,154,001 10/ 1964 Zurawski. 3,190,208 6/1965Styne et 211. 3,193,001 7/ 1965 Meckler. 3,246,137 4/1966 Zagel.3,383,811 5/1968 Ades 52128 FOREIGN PATENTS 705,764 4/ 1965 Canada.

NORTON ANSHER, Primary Examiner R. L. MOSES, Assistant Examiner US. Cl.X.R.

